[dj_axl]

During the first 30 days after an IPO, the underwriters are not allowed to lend shares for short sale. Additionally, number of shares are limited. The entire float is not available on the first day of trading. So today, it is probably impossible to short. 30 days from now, it should be available to short.

http://cash.investopedia.com/ask/answers/05/062905.asp

[icedpulleys]

I've heard that larger banks and brokerages (not the underwriters) will start making shares available for shorting as early as Tuesday, which should help ease the share price down.

[spitfire]

put options?

[krishna2]

Options are available for trading only after a certain number of days (generally 60 to 90 days, but in some cases much earlier than that).